MICROSTRUCTURE OF INTERFACE BETWEEN Y-MODIFIED REACTIVE ION PLATED Ti(Y)N COATING AND SUBSTRATE STEEL A3

The fine rnicrostrueture of the Y-modified ion plated Ti(Y)N coating/substrate steel A3system has been examined by means of TEM and microdiffraction technique.It was revealedthat the interface consists of 3 sublayers,i.e.α-Fe+Y_6Fe_(23),Ti+Y+FeTi and Ti_2N+YN+Ti_xN_y.The thicknesses of them are about 200,50 and 120 nm respectively.The phases inthe transition area seem to have certain orientation relations.The mechanism of interfaceformation has also been discussed.